Controlling the temperature of rubber-working rolls



June 29 ,1926.

M. A. MARQUETTE CONTROLLING THE TEMPERATURE OF RUBBER WORKING ROLLS Filed May 8, 1924 BY v IIIVVENTOR;

A TTORNEY.

Patented June 29 1926.

UNIT ED S T A T E 1,590,638 PATENT OFFICE.

. neuron in menoun'r'rn, or cmcornn FALLS, uassacnusnr'rs, assrenon To run rIsx RUBBER COMPANY, orcnrcornr: rams,- MASSACHUSETTS, a conrona'rron "OF MASSAGHUSETTS.

CONTROLLING THE-TEMPERATURE OF RUBBEE-WORKTNG ROLLS.

Application filed Kay 8;

This invention relates to the working or rolling of plastic material such as rubber, and has for its object the control by rapidly responsive means of the temperature of the rolls by .which the rubber is worked or sheeted. 7

Referring now to the drawings, in which the invention is shown as applied to a calender for sheeting rubber stock,

Fig. 1 is a front elevation of a calender embodying the invention; and I Fig. 2 is a section thereof online- 2-2 of Fig. 1. v

In the working-of plastic material such as rubber, and particularly in the calendering of rubber to produce either sheeted rub her or rubber-coated fabrie it has been customary to regulate the temperature of the rolls by admitting hotor cold water into their hollow interior. Due to the heavy pressure to which these rolls are subjected in use, it is necessary that they be made strong and the thickness of theroll walls this required slows down the transmission of heat from the interior to the exterior of the rolls. Especially when it is desired to control the temperature of the rolls by auto-, matic devices, this time lag causes wide variations in the actual temperature of the 39 working surfaces of the rolls. For example, suppose that due to a temporary cause the rolls become overheated on their surfaces.

To correct this cooling water is admitted totheir interiors. Inrolls of the usual thickness the effect of this water may not apear at the roll surface for several minutes, y which time the temporary cause of heat ing may have disappeared. As sogn as the roll surfaces have dropped to the proper temperature the su ply of cooling wateris shut off or decreased but the cooled interiors of the rolls continue to exert a cooling action on the exteriors for some time, thereby reducin the temperature of the working surfaces be ow what is desired. 3

' In hand controlled machinery of this type it is possible for a skilled operator to judge the cause of the original fluctuation and vary the time of application of the internal water'accordingly. This reduces the fluctua- This diiiiculty has, however, practically prevented the use of automatic temperature controlling devices. By my invention control of the working sur- 1924. Serial No. 711.938.

faces of the rolls is made practically instantaneous, and the use of automatic control devices is made practical for the first time. The principle of my invention is the use of a spray of water or other cooling medium against the roll surfaces before they come into contact with the rubber. The water first cools'the, surface of the roll, the body of which is kept at a temperature slightly higher than that desired on its operative surface, by its lower temperature and then by the heat required to vaporize it. On account 'of the normal working temperature of the rolls being relatively high the water will evaporate so rapidly that the rubber will not be wet. This method of cooling may be used without any other temperature control, reliance being placed upon the heat generated by the working of the rubber to keep the rolls-warm;'but preferably it is used in conjunction with the usual internal '1 circulation of water, the internal water being used to control the temperature roughly and the spray to keep the-temperature of the roll surfaces constant. 2

.In the drawings I have illustrated the application of the invention to a rubber working calender of the usual type, having three stacked rolls 10, 11 and 12, carried by a frame 13 and connected by suitable gearing- 14. Between the rolls 10 and 11 is placed 8 the feed 15 of rubber which, by the action of the rolls, is formed into a sheet 16 which passes between rolls 11 and 12 to a suitable delivery oint. Adjacent each roll is placed a pipe 1%, perforated to eject a spray of 9 water against its respective calender roll under the control of valves 18. Instead of spraying devices of this type the water may.

be directed against the rolls by atomizing k 1 devices of any usual type. As a precaution against the water on the roll not being vaporized entirely before reaching the rubber, wipers 19 may be placed against each roll at points beyond the spray;

The middleroll 1-1 is shown asbeing cooled by a. spray located'at the left in Fig.2, act'- ing to cool the roll before it contacts with the 1 feed of rubber 15. If desired, in order to further. regulate the roll temperature before nearing the lower roll, and as a substitute for/or an additiony to the7tirst nlilentiloneg s re; a second spra pipe 1 may a p ace all t e right of the roll. The spray from this pipe may act directly on the rubber it'- self, or may act on the roll surface, the rubber sheet being carried around it by passing over a roller 20.

A similar system of cooling may be a lied to the mixing mills commonly usedture of a roll for workin 'p astic material,

consisting in subjectin t e surface of the roll to the action of a cat conducting medium in controlled amounts, and d ing the roll prior to contact with the materlal.

2. A method of controllin the temperature of a roll for worh'ng p astic material, consisting in maintaining the roll at a temperature slightl higher than that desired, and locally coo g the surface of the roll to the desired degree prior to the contact ofthe roll surface with the material to be worked.

3. A method of controllin the temperature of a roll for working consistin in causing partic es of water in controlle quantities to contact with the roll during its rotation, and drying the roll prior to contact with the material.

4. A cooling device for a rubber working calender conslsting of water spraying devices located adjacent the calender rolls and directed against the surface of the rolls, means for controlling the quantit of water to be thus sprayed, and means or dryin the rolls rior to contact with the materia 5. In t e manufacture of sheet like articles from a hot plasticmaterial, the method of controlling the temperature of the sheeting rolls which consists in sub'ecting a portion of the outside surfaces 0 the sheetin rolls to the action in controlled amounts 0 an=agent adapted to absorb heat rapidly from the sheeting rolls.

MELVON A. MARQUETTE.

astic material, 

